1. Field of the Invention
The present invention pertains to artificial lenses for the eye and, more particularly, to intraocular lenses for implant in the anterior chamber of the eye.
2. Discussion of the Prior Art
The implantation of an artificial intraocular lens in an eye after removal of the natural lens due to a blindness-causing condition, such as cataract, has become an accepted practice. Such intraocular lenses are normally positioned in the posterior chamber of the eye, secured to the iris, or positioned in the anterior chamber of the eye. Many surgeons prefer anterior chamber intraocular lenses since implant in the anterior chamber is easier for the surgeon than implant in the posterior chamber; and, additionally, in many cases only anterior chamber intraocular lenses can be implanted due to medical considerations. Many intraocular lenses designed for implant in the anterior chamber have suffered the disadvantages of creating medical problems due to stiffness, requiring many sizes to be available for eyes of different sizes and causing too much pressure against the angle structure where the cornea and iris intersect inducing various elements of the UGH syndrome and unacceptably high incidence of cystoid macula edema.
U.S. Pat. No. 4,575,374 to Anis discloses a four point fixation intraocular lens for implant in the anterior chamber; however, the embodiment illustrated in FIG. 1 is insufficiently flexible inwardly and outwardly while being too flexible rearwardly and forwardly thereby providing increased opportunity for iritis and/or cornea damage to occur. To this end, it is noted that the foot portions are designed to flex independently of the leg portions with the leg portions being insufficiently flexible by design. With respect to the embodiments of FIGS. 4 and 7, projections extend laterally from opposite sides of the lens body creating a structure difficult to implant through a minimal incision; and, additionally, the holding members are provided with intermediate portions such that the foot portions flex independently of the leg portions. Additionally, the intraocular lenses of both embodiments are designed to be positioned within the anterior chamber in contact with the forward portion of the iris.